


Know Your Numbers

by Temporarily



Category: Death Note & Related Fandoms, Death Note (Anime & Manga), 約束のネバーランド | Yakusoku no Neverland | The Promised Neverland (Anime), 約束のネバーランド | Yakusoku no Neverland | The Promised Neverland (Manga)
Genre: Additional Warnings Apply, Alternate Universe - Yakusoku no Neverland | The Promised Neverland Fusion, Crossover, Emotional Hurt/Comfort, Families of Choice, Friendship, Gen, Implied/Referenced Suicide, Mystery, Psychological Horror, Self-Harm, Shinigami Eyes, The Promised Neverland Spoilers, an absolute clusterfuck of spiraling mental health
Language: English
Status: Completed
Published: 2021-01-15
Updated: 2021-01-15
Packaged: 2021-03-12 22:14:11
Rating: Teen And Up Audiences
Warnings: Graphic Depictions Of Violence, Major Character Death
Chapters: 1
Words: 3,260
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/28767648
Author URL: https://archiveofourown.org/users/Temporarily/pseuds/Temporarily
Summary: Wammy's House is an idyllic place where children live without fear and want for nothing. All Mello desires is first place in the tests. But when Beyond Birthday discovers the secret behind why L left, and the fate he was running from, the illusion of the orphanage quickly unravels.Mello gets left behind. Out of desperation, he makes a deal.-A Promised Neverland Crossover-
Relationships: A & Beyond Birthday, Beyond Birthday & Mello | Mihael Keehl, Matt | Mail Jeevas & Mello | Mihael Keehl
Kudos: 2





	Know Your Numbers

**Author's Note:**

> I am SO EXCITED for the next season of The Promised Neverland!!! I've been working on this Death Note crossover ever since I finished the first season. I'm still working on the first arc, but this chapter works as a one-shot so I thought I'd put it out to see if people are interested. 
> 
> This is set a few decades before the events of The Promised Neverland, and it focuses on Mello's relationship with Beyond Birthday during his final month at Wammy's House. I hope you like it.

Mello always had a whip-sharp competitive streak. At a mere four years old he was paying attention to who got the best grades at Wammy’s House, trying to figure out how to steal the top spot. As it happened, the person who scored number one in every test by a landslide was Beyond.

Mello began paying close attention to Beyond. He wondered if his strange behaviors were the result of an idle mind or an elaborately constructed disguise. Eventually, the older boy noticed Mello’s attention. He didn’t normally interact with the younger kids at the orphanage but Mello was interesting enough to tolerate. The blond spat and swore childish curses with such venomous intent when he called you a poop, it almost sounded as bad as calling you a shitstain on humanity. He was an ambitious little thing with more spine than a giraffe and more stubborn will than an ass. Once he got it into his head that Beyond should tutor him, well… It was easier to just go along with it. It surely wouldn’t do either of them harm, this mutual observation.

The two made an odd pair. Beyond liked to flaunt his accomplishments; Mello ate up everything he served even as he told Beyond each word coming out of his mouth was trash. Mello called him a show-off, a know-it-all neener, and a teacher’s pet. Beyond didn’t pay mind to any of his insults except the last one. To be a teacher’s pet was something he could not abide, and he made sure to show Mello just how much the adults hated his uncontrollable behavior.

Roger screamed himself hoarse over the state of his ties and Beyond was grounded for a week. But the experiment was worth it because it made little Mello’s eyes widen and shine. He worshiped the ground under B’s bare feet from that day on.

Just as Mello idolized Beyond, Beyond idolized someone who was no longer at the house. L Lawliet. He spoke of Lawliet often. However, the more Mello listened the more he realized how strange Lawliet was, even by Wammy standards. The strangest thing about him? He was never adopted. The kids who remember him think he ran away, but no one knows why. Alter, Beyond’s best friend and roommate and consequentially Mello’s rival for Beyond’s time and attention, became particularly bitter whenever Lawliet was brought up. One afternoon in the library they shut their book with a snap in the middle of a conversation and said,

“I wish you’d stop  _ obsessing _ over this! L abandoned us B, he’s not coming back.” With that, Alter left. Mello examined Beyond’s pinched frown and crooked fingers curling and uncurling on the desk.

“Is that true?”

“…No. L had a reason for leaving. One I will discover.” Later, there were times when Mello wished Beyond had simply left the whole mystery alone.

January 1, 1997

Mello can tell something is different that morning. It’s Matt’s fifth birthday so no one else notices, but Beyond never comes to breakfast. Mello tracks him to the library only to stop short, unsure if he should approach. Beyond is sitting at his usual table without the usual spread of books around him. His angular shoulders are shaking. Shaggy dark hair forms a curtain around his face but it’s not long enough to hide how he’s gnawing at his thumb. Mello can see blood. B’s bitten half his nail off.

Mello approaches and gently pulls Beyond’s hand away from his mouth, pressing it to the table.

“B,” he calls. It’s only then that the older boy stops grinding his teeth and focuses on him. Red is smeared at the corner of his mouth.

“Mihael.”

“What?”

“I see you, Mihael.”

“My name’s Mello.” Beyond pauses. He looks down at his hand and seems surprised.

“Of course. My mistake.” Mello hands him a present pilfered from the breakfast table.

“I brought you jam.” The sight of the jar brings a smile to Beyond’s face. He twists the lid open, scoops out the jam with his fingers, and stuffs it in his mouth. Then he uses the sticky, bloodied hand to ruffle Mello’s hair.

Under normal circumstances, Mello would punch anyone who besmirched his hair like that. He’s  _ proud  _ of his hair, he gets compliments for it all the time and he takes good care of it, unlike Beyond’s bramble-mop. But as he watches the sticky-fingered bastard consume his strawberry jam Mello is seized by irrational terror. Half of him wants to run screaming for Roger so he can tell the caretaker Beyond isn’t acting right. But since when has Roger been on their side? They’re both troublemakers.

“Thank you Mihael.”

“Mello,” he corrects. “Are you okay B?” Beyond hums. The attention he’s paying the jam is interrupted long enough for him to look Mello in the eyes. He glances at the space right above Mello’s head before his gaze flicks down again. His smile widens.

“Did you know I can see your numbers?”

“What?”

“I can see your numbers. I used to think they were a countdown to the day we’re adopted, but now I know the truth.” Mello doesn’t understand what’s wrong with his friend and he hates that. He hates not understanding things as a rule, but this is personal. He feels that barely suppressed fear rise again when B leans in close and asks, “Would you like to know your numbers, Mihael?”

Mello can’t do anything like this. His best course of action is to find A. Hopefully they can help.

“Enjoy your jam Beyond.”

“See you later Mihael.”

After that, Beyond seems to get better. Better in the sense that he isn’t gnawing off his fingernails and seeing things. But he becomes placid, changed. Before, Beyond gave no fucks and did whatever he wanted, no matter how it frustrated the adults. Now Mello sees some lazy creature unconcerned with its surroundings prepared to rip something apart out of annoyance or sheer curiosity. Every time Roger expresses relief that Beyond has grown out of his difficult phase and makes pointed looks at Mello, the blond wants to scream. How can he be so blind and stupid?

Alter rarely leaves Beyond’s side. It's obvious A is worried about their friend, but they're also dealing with their own problems. They jump at every loud noise and eat very little. Once during the daily testing, they break down crying and leave the room.

“Leave it Mel,” Matt whispers as he watches the older boy disappear. Beyond doesn’t even look up from his screen. “Papa will know what to do.”

But that’s part of the problem, isn’t it? Papa and Roger know everything. Mello knows nothing and Beyond’s dangerous intent, Alter’s fear, it’s all directed at the adults. They’ve been distancing themselves to keep their secrets and Mello isn’t brave or stupid enough to confront them about it.

Mello goes to the library and doesn’t come out until he’s read the first introductory psychology book he can find front to back. When he’s finished, he feels like he has little more than labels for problems and no solutions.

January 9th, 1997

“Mello?” The five-year-old immediately perks up. Beyond must be feeling better if he’s stopped calling him Mihael.

“Yeah B?” The older boy is staring across the dining hall. Through the doorway of the kitchen, they can see Alter at the sink washing dishes. At least, they should be washing dishes. They haven’t moved for several minutes. A younger kid tugs at their apron, trying to pass them her dirty plate, but A is too deep in their head to notice.

“What do you do to help Matt when he is upset?”

“I punch him and tell him to get over it.” B frowns, dissatisfied with this answer. Mello sighs and laments at how the joys of sarcasm are lost on this guy. “I annoy him until he tells me what’s making him upset. Then if I can’t get rid of it, I hug him and make him do something else until he feels better.” Beyond nods and idly draws a smiley face in his mashed potatoes.

“That may work. Thank you for your advice Mello.”

That conversation is the last time Beyond calls him by that name.

Beyond begins slipping into the state of mind Mello found him in when he was chewing on his fingernail twenty-four-seven. He lurks in the hallway day and night, crawling on all fours, muttering about death gods and numbers and L. Meanwhile, Alter withers away. They rarely talk and refuse to go anywhere near the dining room or kitchen. It gets so bad that Roger and Papa finally get their heads out of their asses and notice something’s wrong; these aren’t mere eccentricities. Papa tries coaxing Beyond into standing up like a normal fucking human being instead of rolling down the halls at three in the morning laughing like a lunatic. Roger becomes increasingly frustrated when Alter won’t eat. Mello can see that Matt was wrong: The adults don’t know how to do shit. They’re not helping and they’re far, far too late. Roger at least cares enough to curse them, but it’s hard to tell if Papa is even trying.

Mello resigns himself to the distance separating B and A from everyone else. There’s something inside him that warns him away from getting too close. Because when the day comes that their numbers run out, it won’t be pretty.

That day comes all too soon for Alter. One afternoon, A and B don’t return from a game of tag. Papa goes out looking after night falls and only comes back with Beyond. He’s slouching wherever he’s led, staring at nothing. He’s been laughing and joking in ways no one can understand for weeks on end and now, he’s silent.

Beyond’s adoption is announced the very next day.

January 21st, 1997

12:00 AM

Mello almost screams when he wakes up and Beyond is crouched over him. For half a second, his eyes flash red. Mello dismisses this as a dream-scrap induced hallucination and asks what time it is.

“Midnight,” Beyond says with a feral grin. “I’m twelve now.”

“Happy Birthday Beyond.” Mello hopes this will be enough for B, and he’ll let him go back to sleep. He has no such luck. Beyond calls him Mihael, tells him to follow, and slouches out to the hallway. Mello should know better by now but still, he follows.

Beyond brings him to the attic and presents Mello with two misshapen pastries that are supposed to be jam-icing cupcakes. He sticks a candle in his own and moves to light it but gets distracted by the small bright flame. He uses the first match to light a second one and offers it to Mello.

Mello takes the match. He stares at the flame and remembers how they used to play with fire for hours. He never knew where B got the matches, but it was exhilarating doing something forbidden, watching something so destructive and beautiful. Now it seems childish. Fire isn’t dangerous if you know how to control it. Mello licks his fingers and pinches the match out.

B lights his candle. Mello hums Happy Birthday and B blows it out. They eat their jam cupcakes. Mello asks B what he wished for.

“I wished to turn thirteen. I’ll wish for everything else after that.” Then, crouched among the dust and forgotten things, B tells Mello a horror story about Shinigami and death farms. Then he tells Mello that this story is true.

Mello doesn’t believe him. Beyond tells him that’s okay. He just needed someone to know before he leaves.

Mello says, “I hope you find a family who understands you. Papa and Roger were twits. They never even tried, they just wanted you to be good.” Beyond shifts on his toes and looks at the stream of moonlight coming through the solitary attic window. He prophesies:

“I will never find a family outside this house, Mihael. The Shinigami will try to kill me tomorrow. I don’t know if they’ll succeed, but I do know that A is gone and L is out there, beyond the gate. Now that I know the truth, the only thing left to do is find him.” It’s only then that Mello considers B might be telling the truth. He certainly believes it enough to speak with conviction. That frightens Mello.

“Don’t go B,” he whispers. This is pathetic. Mello has always been dismissive of the kids who burst into tears and whine every time someone leaves for adoption, but now he understands them. Even though B has become terrifying and makes no sense and doesn’t brush his hair, Mello doesn’t want him to go.

“Mihael Keehl,” Beyond muses. “Whoever your mother was, she picked a good name for you.” The older boy stands, each limb unfolding and elongating. His crooked fingers ruffle Mello’s hair. “You’ll be okay. Michael needs no guardian.” Mello doesn’t have a clue what the fuck he’s talking about. Beyond disappears down the ladder. But when Mello squeezes his eyes shut he finds, against all rational thought, that he does believe Beyond.

10:00 PM

B leaves the house looking like an animal trapped in a corner, teeth bared. Papa comes back with a limp. Mello doesn’t cry at all but Matt can tell he’s upset, so he gives him a hug and tries to distract him.

It doesn’t work.

January 22, 1997

4:31 AM

Plagued by nightmares, Mello visits the library. When he turns past the shelves and looks at Beyond’s favorite table he half expects to see him there. Beyond was never as much of a book-nerd as Alter but they both frequented the library. Beyond would make tortured food paintings or chemical concoctions. Alter would remind him not to get jam on the books.

There’s no one there but some toddler with a jigsaw puzzle. Mello tries to remember the pipsqueak’s name. Near?

Near sees Mello and blinks. Mello sneers and walks away.

10:59 AM

“Is it true?” Papa looks up from the papers at his desk, puts down his pen, and lowers his spectacles. “Beyond told me everything last night. Is it true?”

“I’m afraid I’ll need more information than that Mello. I haven’t the slightest idea what Beyond told you.”

“He said that this is a farm, and you give us to death gods who eat us to add our lifespans to theirs. Is it true?” Mello waits for Papa to deny this, to write Beyond’s story off as the deranged ravings of a mentally disturbed delinquent on the eve of his departure to someplace people will know how to take better care of him than they can. Mello eagerly anticipates calling him out on his bullshit.

“Yes.”

“Oh.” The older man gestures to the chair on the other side of his desk, and Mello sits. He takes a moment to re-evaluate the rules of his entire world. There was still a part of him that had been in denial until this moment.

Papa is an enemy. Uncle Roger is his accomplice. Everyone else Mello knows is going to die and be eaten. It’s only a matter of time until it’s his turn. Twenty-two days ago, Alter and Beyond discovered a secret room and learned about Shinigami. They’ve been rapidly losing their minds ever since. Mello can’t blame them. He doesn’t feel completely stable right now himself.

And here he thought he would be happy when he finally understood.

“Papa, what’s your real name?”

“My real name is Quillsh Wammy, although I have gone by many others throughout my life.” Good. Mello doesn’t think he can stand to call this man  _ Papa  _ anymore.

“What happened to A?”

“A climbed the walls surrounding these grounds and discovered the cliff on the other side blocking any hope of escape. In despair, they threw themself over the edge and fell an unimaginable distance. It’s too dark down that chasm to measure exactly how deep it goes.”

“…Was B there?”

“He was. He could do nothing to help his friend.”

“What happened to B?” Wammy chuckles fondly.

“I do believe Beyond is the first case of a twelve-year-old human successfully fighting off a Shinigami with nothing but rage, adrenalin, and whatever meager weapons he could find.” Mello feels hope renewing and soaring. B made it out. It’s possible to beat them. If he did it, Mello can do it, and he can take Matt with him. “However, B must still go through the heart of this facility before he can escape, which is swarming with Shinigami. I’m sure he’ll be caught soon. Would you like me to tell you when he is?”

“Don’t bother.” He doesn’t want to hear it. “Why are you telling me this? Don’t you like your secrets?”

“You already know the secret of this place. To better prevent another incident like this one, I believe a policy of honesty would be the best way forward.”

“Honesty huh? What if I decide to be honest? So honest that I tell everyone else what you’re doing?” Wammy smiles at him indulgently.

“Oh, Mello... You really are a troublemaker. Who will the rest of the children believe, an attention-hog like you, or their beloved father?”

“Me, ‘cause I’m telling the truth.”

“You do realize I hold your life in my hands, don’t you?”

“Yeah, and that sucks, but I’m not stupid. If you want me to keep quiet, you’re going to have to give me a good reason not to be the brattiest kid in this orphanage.” Wammy shakes his head.

“So transparent. Very well. I can’t promise you your life, a bright boy like you will be ordered for harvest sooner or later. The most I can give you is until your twelfth birthday, and that’s entirely dependent on your behavior.

“I’ll take it, and you have to promise Matt will stay until he’s twelve too.”

“Matt? …Of course. You would wish to guarantee his safety. I can do that on two conditions: One, you tell him nothing, and two, he never places last in the tests.”

“I’ll make sure that won’t happen. But there’s one more thing.” The old man waits expectantly. “I want to know what the real world is like, the one outside this orphanage. You don’t have to waste your time telling me about it, just bring me things and I’ll figure it out.”

“Done.” Mello glares at him, suspicious that this is so easy. Are they that desperate to keep him quiet?

“Really?”

“Yes. I will bring you things, within reason. I can’t give you any live animals or weapons. But it would be counter-productive to repress your curiosity. I hear curious minds are most filling.” Wammy’s mustache twitches upwards, and Mello glares at him. “My apologies. You probably found that joke…  _ distasteful _ .”

“No shit.”

_ “Language.” _

“I’ve got seven years to live, I’ll say whatever I damn well want." Wammy considers this and then relents with a sigh.

“Do try to tone it down around the younger children.”

“No guarantees old man. And don’t expect me to turn into a sheep cause you’re giving me stuff! This is all just to motivate me to pretend things are normal.”

“I wouldn’t dream of it.” It seems that there’s nothing left to say at this point. Mello turns to go.

“Mello—” Wammy opens and shuts his mouth, struggling to find the words. “I suppose any apology on my part would be worthless.” Mello slams the office door closed.


End file.
